I was reading Murphy's post at his blog, and in the same hour, I got a notice from a buddy of mine that he was publishing a new book. My buddy, if you click on the link, is a fellow named Darrel Poole, Darrel got his PhD studying police ethics, and he still works as a beat cop.
At any rate, Darrel studies police ethics, and Murphy was talking about police ethics, so it's time to tell a story about a lie detector.
You'll notice that I didn't say anything about a polygraph. There are no polygraphs in this story. What we'll use is a good old-fashioned police lie detector. Our story starts at a small city police office in north Louisiana. About 40 sworn officers. The protagonist in our story is a fellow we'll call Jerry. Jerry was a detective in this small agency, one of a half-dozen plainclothes officers.
The detectives shared one room in the police building. One large room with six desks where the detectives did their business. Next to Jerry's desk was the office copy machine. It sat on a table and when someone wanted a copy, they came over to the copier by Jerry's desk.
One day, at the small hospital in town, Jerry noticed an EKG electrode laying on a table and asked about it. It was broken, he was told and they were throwing it away. Jerry asked, and took it. Jerry went back to his office later, and taped the end of that electrode to the back of the copy machine. Jerry made a sign that said HE's LYING in big letters and put it in a desk drawer.
The scenario went like this: When Jerry needed to interview a suspect that he thought was lying, he'd surreptitiously slip that sign into the copy machine, then he'd ask the subject if he would agree to take a lie detector test. If the subject agreed, Jerry would, with great ceremony, retrieve the suction-cup end of the EKG device, coat it with a tube of vaseline, and stick it on the forehead of the subject.
So, there the suspect sits, a small wire trailing down his nose, going to the back of the "Lie Detector". Every so often, Jerry would stop the interview, punch the button on the machine to get a "report" and retrieve a copy that said, HE's LYING".
Jerry made more than a few cases with his Lie Detector. Occasionally, he'd be asked about it in court. The conversation would normally go like this:
Attorney: "Detective, my client tells me that you subjected him to a polygraph exam. Do you have the results of that polygraph?"
Jerry: "No, sir. Our department doesn't have a polygraph."
Attorney: "So, it's your testimony that you never subjected my client to a polygraph examination."
Jerry: "That's right, sir. The nearest polygraph that I'm aware of is in Shreveport, and we very seldom use it. I certainly never took your client to Shreveport."
It's a true story. As they used to say in the old series Dragnet, "This story is true, but all the names have been changed to protect the ignorant."